Crossover Hop Test: protocol for return to sport

Among return-to-sport batteries after a knee injury, the crossover hop test is one of the most demanding: it combines forward single-leg hops with a lateral crossing component, adding a rotational and knee stability challenge that simpler jumps don't require as much.

What does this test measure?

This test measures the distance covered over three consecutive single-leg hops, alternately crossing a central line. It assesses strength, power, and neuromuscular control of the hopping leg, especially in the frontal and rotational planes — the planes that demand the most from the knee in sports involving changes of direction.

It's typically used as part of a hop test battery to decide whether an athlete is ready to return to competition after an anterior cruciate ligament (ACL) injury or other knee injuries.

Equipment needed

• Tape to mark a center line on the floor
• Measuring tape (at least 3-4 meters)
• Firm, non-slip floor space

Test protocol

1. Mark a straight line on the floor at least 3 meters long
2. The subject stands on one leg next to the line, at the starting point
3. They must perform three consecutive forward hops, alternating sides of the line on each hop (i.e., crossing the line from one side to the other on each repetition), always landing on the same leg
4. The landing of the third hop must be controlled and held (no extra steps, no loss of balance) for at least 2 seconds
5. Measure the total distance from the starting point to the landing point of the third hop
6. Repeat 2-3 attempts per leg, with rest between attempts, keeping the best valid attempt
7. Repeat with the other leg

Common mistakes

• Not requiring a controlled final landing (a "bouncing" landing or extra steps invalidates the attempt)
• Allowing the subject to step on the line instead of crossing it cleanly
• Not allowing enough rest between attempts (fatigue affects performance)
• Comparing results without calculating the symmetry index, relying only on absolute values

How to interpret the result

Limb Symmetry Index (LSI)	Interpretation
≥ 90%	Criterion met for considering progression toward return to sport (combined with other criteria)
80-89%	Moderate deficit — keep progressing before moving to maximum-demand tasks
< 80%	Significant deficit — not advisable to progress to maximum-intensity training/competition

The LSI is calculated as: (affected leg distance / healthy leg distance) x 100. As always with these tests, it's one criterion among several in a decision-making process, not the sole factor for clearing return to sport.

Relationship with other tests

The crossover hop test is often used alongside other jumps from the same battery:

• Side Hop Test — more focused on the frontal plane with repeated, shorter-amplitude jumps
• Jump-Landing Control Test — complements the distance/performance assessment with a qualitative landing analysis

Track the process with Movalytics

In return-to-sport processes, this hop test battery is typically repeated several times over the weeks. With Movalytics you can log the distance for each leg in each session, and the app helps calculate and visualize the evolution of the symmetry index, giving you objective data when deciding whether to progress to the next phase.

Frequently asked questions

When can this test start being used in ACL rehab? Only in advanced phases, once the athlete already tolerates single-leg hops with good technique and has an adequate strength base (typically not before 4-6 months post-surgery, and always under the judgment of the rehab team). What if the LSI result is good but the athlete is afraid to jump? The psychological component is just as important as the physical one in return to sport. A good LSI isn't enough if there's fear or lack of confidence; it should be combined with confidence/readiness scales. Can this test be used without a prior injury? Yes, it's also useful as part of preventive screening in athletes who perform direction changes, to detect leg asymmetries before they become a problem.